Tracking your ads is important. It lets you know what's working and what's not. It tells you where your customers are coming from. Below are some tools that will help you track your advertising.
Bit.ly – A popular URL shortening and tracking service.
Goo.gl – Google's URL shortening service. Provides stats.
Yourls.org – A URL shortening and tracking script you can download and set up on your own website.